The specification relates to device proximity detection.
Existing systems usually take advantage of Global Positioning System (GPS) to locate a user device and determine proximity between different user devices. However, GPS is power intensive and used infrequently, which results in a possibility of stale data. In addition, if GPS is used indoors, the GPS signal may not be available and, as a result, the user device switches to using WiFi or cellular means of location detection, which are much less accurate.